Patent Document 1 discloses a wireless power transmission system that transmits power through capacitive coupling. The wireless power transmission system described in Patent Document 1 is constituted by a power transmission apparatus that includes a high-frequency high-voltage generator, a passive electrode, and an active electrode, and a power reception apparatus that includes a high-frequency high-voltage load, a passive electrode, and an active electrode. As the active electrode in the power transmission apparatus and the active electrode in the power reception apparatus approach each other with a gap interposed therebetween, the two electrodes capacitively couple with each other, and power is thus transmitted from the power transmission apparatus to the power reception apparatus. This wireless power transmission system of a capacitive coupling type is advantageous in that the amount of transmitted power per unit area can be increased and the degree of positional freedom along the mounting surface can be increased.
Patent Document 1: Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2009-531009.
However, the wireless power transmission system described in Patent Document 1 has a problem in that, when a reference potential of the power reception apparatus varies relative to an earth potential, a load circuit of the power reception apparatus malfunctions during power transmission in a device, such as a touch panel, that a user touches. In addition, there is another problem in that, when a reference potential of the power transmission apparatus varies relative to the earth potential, unwanted noise is conducted to a power supply line. Thus, in a wireless power transmission system of a capacitive coupling system, it is important to suppress a variation of a reference potential during power transmission.